Problems mounting disk images: Try booting in safe mode; clearing certain caches

If you are having a problem where disk images won't mount, try booting in Safe Mode (by holding down the Shift key while starting up), then re-attempting mounting of the disk image.

This solution is particularly useful for a situation where you would like to attempt re-application of a Mac OS X combo updater (a common workaround for issues that occur after an incremental Mac OS X update), but are unable to mount the combo updater disk image.

Prior to booting in safe mode, however, you can delete the following files:

• /System/Library/Extensions.kextcache
• /System/Library/com.apple.kernelcaches

These, and other cache files, are automatically deleted when you boot in safe mode, but you can potentially save some time by trying deletion of these files (then logging out and back in) and re-attempting disk mounting.

Feedback? Late-breakers@macfixit.com.

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